Water treatment systems are designed to condition incoming water in some fashion. A variety of water conditioning processes are available. For instance, water conditioning can be a distillation process, a demineralization process, a reverse osmosis process, or a filtration process, to name only a few. The demineralization process is of particular interest.
The demineralization process removes dissolved compounds, for example, calcium and magnesium compounds, from water. Since these compounds can become insoluble in water, particularly at elevated temperatures, they can precipitate and create scaling problems by adhering to piping and other surfaces. Therefore, water containing these less soluble compounds is called “hard” water. The scale can cause problems by restricting flow through pipes and may appear as a residue in bathroom showers, dishwashers, and in other areas of the home. The demineralization process removes the ions that cause the scale. This process is more commonly referred to as water softening.
Water softeners, like those found in many households, demineralize the water provided to the house by a public utility, private well, or other source. Water softeners include a treatment tank containing a plurality of resin media. The media is generally made of a synthetic polystyrene ion-exchange material. During the treatment process, the incoming hard water is passed through the media. The ion-exchange process removes the calcium and magnesium ions, the “hard” ions, and exchanges them for “soft” ions. For example, sodium is a soft ion because sodium compounds are more soluble in water. Therefore, sodium compounds do not have a propensity to precipitate onto the surfaces nearly to the degree as that of the calcium compounds. The soft water then passes out of the treatment system to a point of use.
A water softening system generally consists of a treatment tank, a brine tank or a regeneration agent reservoir, and a water control valve. The valve controls the flow of water between the source, the point of use, the regeneration agent reservoir, and the treatment tank. The water control valve directs water to the components of the water softening system according to a prearranged set of cycles, or water flow directions. Generally, the cycles consist of a service cycle, a backwashing cycle, a regeneration refill cycle, a regeneration cycle, and a fast rinsing cycle.
The service cycle water directs untreated water to the treatment tank where the water is softened or treated. The treated water flows out of the treatment system to its point of use, as needed. The service cycle takes sodium ions from the media and adds them to the untreated water to soften it. At the same time, the hard water ions are taken from the water and adsorbed onto the media. So, during the service cycle, the media is depleted of sodium ions and is loaded with the hard ions. Eventually, the media becomes ineffective at softening. Therefore, the media must be periodically backwashed and regenerated.
The media should be backwashed prior to regeneration. Water flow through the media is reversed during the backwashing cycle. The reverse water flow flushes sediment and other contaminants, such as oxidized iron, from the media and into a drain as waste water. In addition, backwashing prevents the media from becoming packed or channeled and assures consistent operation of the media during the service cycle.
During the subsequent regeneration cycle, a regeneration agent, typically a sodium chloride solution, is added to untreated water. A solution of sodium chloride and water is passed through the media. The flow direction of the regeneration agent through the media is important for efficient regeneration of the media. There are two configurations for controlling the direction of flow. In one configuration, the flow direction is down, commonly called down-flow or co-current flow. In the other configuration, the flow direction is up. This is referred to as up-flow or countercurrent flow. In both configurations, the media releases a majority of the calcium and magnesium ions into the solution and adsorbs the sodium ions from the solution. The water containing the calcium and magnesium ions, together with any residual sodium ions is waste water. The waste water is directed to the drain.
Following the backwashing cycle the media may be disrupted. If the media does not settle back into position properly the treatment process may be negatively impacted. The fast rinsing cycle generally has two purposes. The first is to forcibly repack the media. The second is to flush any residual regeneration agent from the media.
The control of the water flow to and from each of the system components during each of the cycles is a critical function. Past water control valves precede through a predetermined sequence of the cycles. That is, they proceed through each cycle in a chronological order without exception or variation. In fact, past water control valve designs prohibit variable sequence or cycle independency.
There remains an unfulfilled need to provide a water control valve which can cycle through a preset sequence of operations and change from one cycle to any other cycle without regard to a predetermined sequence to improve the flexibility and efficient response of the water softening system to changing demand. Additionally, there remains an unfilled need to provide a valve that may be configured quickly and easily in the field to operate in an up regeneration or down regeneration configuration.